EEVblog #518 – 9V Alkaline Battery ConstructionPosted on September 10th, 2013 12 comments
What’s inside a 9V Alkaline Battery?
Are they all created the same?
Is Duracell better than Energizer?
Dave opens up Duracell, Energizer, Varta, and a no-name generic Alkaline 9V PP3 battery.
It would be neat to see a time lapse video of the pile type batteries as they discharge. I suspect the layers of zinc would slowly disappear.
I decided to take apart some of the 9v batteries I have on hand here in the USA to compare with Dave’s findings.
Ray-O-Vac is a popular alternative to Energizer and Duracell here. It has has the pile construction like the Australian Vartas. US Patent 5691079 is stamped on the metal plate under the clip terminals.
Energizer is like in the video. I also will stop using them.
I found a Duracell with expiration date of 2015, and it’s similar to the one Dave showed.
I took apart Duracell’s in the late 1970s to use the AAAA cells in my Sinclair Scientific calculator instead of the expensive AAA cells it wanted. The calculator was my first successful kit project. I was a kid with no money and learned that the AAAA cells could be recharged a few times, allowing me to make it through high school with the battery-sucking Sinclair. The construction of the Durcell 9v batteries hasn’t changed much or at all since then.
Now for the good part:
Recently, Mouser started carrying Panasonic 6LR61 9v batteries. I bought some to try them. They have the Duracell-style series AAAA cell construction, and in single quantity are only $2.03. I’ve never gone wrong buying anything from Panasonic, and they are now my favorites.
There is a Chinese brand called Electrix sold at Safeway, which I tried a few years ago. The construction was so horrible that once one of the snap clips fell right off the battery for no apparent reason. I never bought another!
My intuition says the construction with 6 x AAAA would deliver less energy than the pile construction because the pile construction completely uses the 9V battery internal volume while the 6 AAAA will inevitably have about 20% dead space when squeezed together in the 9V prismatic form.
A time lapse of the Energizer corporate drones faces while they are watching this video would be interesting as well
The dry-cell battery should be invented by a Dane named Wilhelm Hellesen around 188x, and he made battery’s under the brand “Hellesens”.
Around 1980 the factory starts to make Alkaline battery’s, later the company change its name to “Alkaline Batteries A/S”. And a bit later they stop to make battery’s and then they sell battery manufacture technology all around the world.
On the patent you show there is a strange name “J.o slashed.rgen Daugaard” is should be “Jørgen Daugaard” but the strange Danish letter Ø had been looked at as what it look like, a O with a slash in it.
I do not think that there is that many battery manufacturers left as there was some years ago, rumours tells that less than a hand full is left that make Alkaline battery’s today.
You walk in order how many battery’s you want, how they should be dress so to speak, and how much you want to pay (the quality of the final product) and they make you battery’s, and they make your competitors battery’s too.
I will not be surprised if only two Alkaline battery manufacturers is left, one that stack the cells, and one that use round cells.
Where do you bought all those broken instrument to teardown?
I’m interesting to get some to have fun too.
Rayovac (reorganized as Spectrum Brands) bought Varta in 2002 so it is not surprising that they have used the same manufacturing process across different production lines since it is presumably cheaper than the the metal canned 4A cells. The Coles branded battery from Korea is also likely from another Rayovac operation.
It will be interesting to see if Duracell and Energizer switch to the stacked pile construction after the patent expires.
I created a battery shield after taking one of these apart and realized I could make a 9 volt stackable shield from the AAAA size batteries inside since their diameter was smaller than the height of the Arduino connector.
I used actual AAAA batteries though since, like Dave pointed out, the 9V cells use batteries are slightly smaller than true AAAA’s.
It was successfully funded on Kickstarter.
Check it out:
Nice information Thank you for sharing……….
I thik this is very useful information .Thank you for sharing…..
it is a problem choosing 9v batteries. Based on apparent construction quality, the Energizers don’t look good.
Rayovac presumably performs similar to Varta based on same technology. Seems to perform poorly at high current drain – presumably a feature of the design. I pulled apart a carbon zinc 9v decades ago and it had a stack of rectangular cells.
Wonder if the Energizer Industrial are any different construction-wise.
To me, the worse characteristic of an alkaline battery is leakage, which damages the contacts of the device they are in.
So maybe lithium is the best option apart from cost and potential for fire….
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